import type { Sql } from "postgres";
import type { AcquisitionOptions, LockConfig } from "../common/types.js";
import type { PostgresBackendOptions } from "./types.js";
/**
 * PostgreSQL backend for SyncGuard distributed locking.
 *
 * Uses postgres.js (porsager/postgres) for transaction-based locking
 * with table storage, server-side time authority, and fence tokens.
 *
 * @module syncguard/postgres
 */
/**
 * Creates distributed lock with PostgreSQL backend via postgres.js client.
 *
 * IMPORTANT: Call setupSchema() once before creating locks to set up schema.
 *
 * @param sql - postgres.js SQL instance
 * @param options - Table names and cleanup config
 * @returns Auto-managed lock function (see: common/auto-lock.ts)
 *
 * @example
 * ```typescript
 * import postgres from 'postgres';
 * import { createLock, setupSchema } from 'syncguard/postgres';
 *
 * const sql = postgres('postgresql://localhost:5432/myapp');
 *
 * // Setup schema (once, during initialization)
 * await setupSchema(sql);
 *
 * // Create lock function (synchronous)
 * const lock = createLock(sql);
 *
 * // Use lock
 * await lock(async () => {
 *   // Your code here
 * }, { key: 'my-lock', ttlMs: 30_000 });
 * ```
 */
export declare function createLock(sql: Sql, options?: PostgresBackendOptions): <T>(fn: () => Promise<T> | T, config: LockConfig & {
    acquisition?: AcquisitionOptions;
}) => Promise<T>;
export { createPostgresBackend } from "./backend.js";
export { setupSchema } from "./schema.js";
export type { PostgresBackendOptions, PostgresCapabilities, PostgresConfig, } from "./types.js";